legacy free

[HondaF1]

Hi.

Im thinking of building a system. I have little experience with legacy free systems. Can someone answer these questions:

1. What is the main advantage of having a legacy free system over a regular system?

2. Does legacy free use like seperate hardware? That is, does a legacy free system need a "legacy free board compatible hard drive/cd writer"...?

3. Is operating system compatibility with a legacy free mother board any different from that of a regular one?

 

[AndyHui]

"Legacy free" generally means items which used to use the ISA bus, are dropped. These include serial ports, parallel ports, PS/2 keyboard and mouse ports, and the floppy drive.

Supposedly it's more efficient. Certainly serial, parallel, mice and keyboards can be replaced with USB type peripherals.

It has nothing to do with hard drives or CD writers.

Operating Systems are generally not too fussed at the lack of ISA items.

 

[MichaelD]

Yeah, I really don't see the big deal either. I've used a legacy free system. All USB and no floppy and I didn't see a darn bit of difference.

Yeah, they run on the ISA bus...but it's not like keyboards need USB 2.0 speeds to work well, you know?

Now, I wouldn't use an ISA NIC or soundcard...that would be ridiculous.

I have a PS/2 KB and a USB mouse. *shrug* Works for me.

 

[HondaF1]

So, is it worth building a legacy free system?

 

[Odeen]

If you don't have any parallel, serial or PS/2 devices, and you don't need a floppy, it can't hurt.

That said, most secondary IDE controllers and a lot of newer SCSI controllers require a floppy disk to install Windows on a drive that they control. I.E. - a Highpoint HPT370/372, Promise PDC20278, Silicon Image SIL3112/3114, etc.. You hit F6 during the initial windows install phase, and insert the driver CD - which Windows adds on the fly to its driver database.

So, if you have a legacy-free system, you either need to install the OS on a chipset-level controller, or use a controller that has a native driver (such as the Promise Ultra100, which, when not updated, still suffers from the 127gb limitation). Even some chipset-level SATA controllers, such as the VT6410 integrated into the VT8237 southbridge require drivers, as do Intel's ICH5R in RAID mode.

AFAIK, Windows Server 2003 doesn't have this limitation, but who wants to game on a server OS?

So, what you're stuck is either using your mobo PATA port for a hard drive on which you install windows (so no RAID), or you have to patch the windows install CD itself (which is non-trivial), or you have to have a floppy drive, at which point you have an ISA system, so it's no longer fully legacy-free.

Most system monitoring chips sit on the ISA bus as well.. so I don't think it's possible to get rid of "legacy" level components altogether and, without being able to do so, you still have an ISA bus with all of its performance bottlenecks, if any, present.


All THAT said, I'd love to see someone come out with an i875P / ICH5 or ICH5R system with no ISA bus components whatsoever.. This assumes that the SMBUS components (i.e. system monitoring) are architecturally able to live off the PCI bus, and either have to run ICH5R in ICH5 mode (i.e. just as a SATA controller, not RAID) or you have to use Server 2003, but I'd be willing to make that sacrifice for a cutting-edge system with one less point of failure.

 

[Peter]

My approach is to gradually migrate. I do reuse e.g. the old keyboard and printer on new system, yes. But whenever I'm out to buy new stuff, I make it something that's NOT a legacy bus item. I do not buy non-USB keyboards or mice anymore, all the flat panel displays I recommend to people are DVI, I give people's computers internal flash card readers rather than floppy disk drives, and so on.
It's 2004, about time we get rid of the 1981 technology that makes keyboard, mouse, FDC, COM and LPT ports.

 

[Zepper]

I don't see the point in legacy free except perhaps on the cheapest systems. After all, they don't give you the ports, but the dedicated hardware IRQ lines that supported them aren't freed up (least I don't think so).
. Personally, I don't want my control devices (kbd, mouse) to be on a shared bus when there are perfectly good ports with dedicated IRQs to support them. And I prefer external serial modems (most of the USB ones are Winmodems too and useless with any OS other than Win - and suck much more CPU time besides).
. Since fully configured mobos are readily available for the same or less $s than the legacy-free ones, why bother? Is some salesman pushing you to buy legacy free or find some on clearance? Probably just wants to move some of that doggo crap off his shelves... Notice that Abit (I think the only mobo maker to try this one) hasn't done it with any of the new chipsets - the AMD one is stuck back at the KT-400, while the 400A and 600 blow on by...
.bh.